I always take info from vendors with a grain of salt. I had thought Nordost recommends 2m power cords but I could be mistaken. I once found a link on these boards to a Nordost Q&A that lists recommended lengths for all types of cables. The PS Audio guy also recommends 2m as “the sweet spot” and said he has a number of theories as to why, inferring that longer than this can be worse.
Regarding pricing, yeah, all HiFi vendors are seemingly making ridiculous margins. I just bought some Herbie’s Cone/Spike Decoupling gliders for my speaker spikes to sit on. They are considered the “budget” option for these types of products (but people report positive results). But for the life of me I can’t see how these would cost a manufacturer any more than a few dollars more than a standard set of furniture sliders from Home Depot. Cable companies get picked on but it’s all types of HiFi vendors really. On the flip side the HiFi market is minuscule. For anyone to be in such a low volume market, it would only make sense if the margins were exorbitant with the small number of people in the market willing to pay.
Of note, yes, the Herbie’s gliders do seem to make an easily noticeable difference. I tried putting them on one speaker and not the other. That made the differences really obvious. But I don’t have experience with similar products and I’m guessing others are effective as well.